Crankcase ventilation control device



Dec. 15, 1964 L. c. PARKER CRANKCASE VENTILATION CONTROL DEVICE Filed Jan. 14, 1964 I ATTORNEY United States Patent dice 3,l6l,i87 Patented Dec. 15, 1964 3,l6l,187 ERANKKIASE VENICELATEQN QQNTRGL EEVECE Leland (1. Parker, Rochester, N.Y., assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Filed .ian. 14, 1964, Ser. No. 337,642 6 Claims. (Cl. ill-1E9) This invention relates to crankcase ventilation systems for internal combustion engines and more particularly to a crankcase ventilation control device adapted to be secured on the inlet tube or snorkel of a conventional air cleaner silencer and including means communicating with the engine crankcase whereby a flow or" crankcase efiluents is maintained from the engine crankcase into the inlet air cleaner at a relatively constant rate throughout all conditions of engine operation from idle to wide open throttle.

It is known in the art to ventilate the crankcase of an internal combustion engine by providing a connection to the inlet of the engine air cleaner whereby the vacuum produced by the inlet air flow draws a quantity of crankcase eiliuents into the engine air inlc it is a common problem of arrangements of this type that if the system is designed to provide a sutlicient ventilating ilow during engine idle conditions then the increased vacuum under wide open throttle will cause a substantially increased flow often to the point where lubricating oil droplets are carried into the engine inlet, adversely effecting engine operation. Moreover, if a suitable flow is maintained at wide open throttle conditions, the flow rate at engine idle conditions will generally be insufficient.

A feature of this invention is that it provides a crankcase ventilation control device to maintain a relatively constant flow of crankcase eiliuents into the engine air inlet over the complete range of engine operation. Another feature of this invention is that the control device includes means for attachment to the inlet tube of a conventional air cleaner and tubular means for connection to the engine crankcase whereby the device may be incorporated on existing engines.

A further feature of the invention is that the control device includes a body having an impact chamber communicating with the engine crankcase and open on the side toward the incoming inlet airstream whereby to utilize intake vacuum to draw crankcase effluents into the engine air inlet and to allow the ram effect of the incoming inlet airstrcam to offset the effect on the flow of crankcase effluents of increasing intake vacuum at higher air flows. Yet another feature is that a butterfly valve is provided substantially blocking, in the closed position, the inlet air passage into the body and substantially covering the open end of the impact chamber, the valve being responsive to increasing inlet air flow so as to move toward an open position unblocking correspondingly the inlet passage and impact chamber opening whereby to maintain vacuum pressure on the impact chamber relatively constant and thereby maintain a relatively constant flow of crankcase effiuents.

Other novel features of the invention will be apparent from the following specification and drawings in which:

FIGURE 1 is a side elevation of an internal combustion engine embodying the invention;

FIGURE 2 is a cross-sectional view or a crankcase ventilation control device according to the invention showing the butterfly valve in the closed position; and

FIGURE 3 is a partial cross-sectional view of the valve of FIGURE 2 showing the butterfly valve in the fully open position.

Referring now to the drawings, an engine it? includes a crankcase 12 and carries a conventional air cleaner 14 including an air inlet tube or snorkel 16 having an outwardly flared end portion 13. A crankcase ventilation control device indicated generally by the numeral 2% is secured to the end of the snorkel 16.

Control device includes a tubular body 22 of generally rectangular cross section open at both ends and having at one end thereof a slotted attaching portion 24 adapted to he slipped over the flared end portion 1? of the air cleaner snorkel l6 and to engage a seal 26 provided to prevent leakage of air at the junction. A clamp 28 retains the ventilating valve in place. Adjacent the attaching portion 24 is an internal flange 30 which engages the end of the flared portion 18 to locate the body 22 and which may provide an additional means for sealing against air leakage.

On the lower wall 32 of tubular body 22 and at the other end from attaching portion 24 are located connecting means including an impact chamber 34% extending across the lower edge portion of body 22 and partially defined by a depressed lower wall portion 36 terminating in an impact lip 38. The impact lip extends beyond the remainder of the inlet end of the body 22 for a distance which is determined by the crankcase eilluent flow characteristic desired as will subsequently be more fully discussed. The upper surface of the impact chamber is deined by a partition dd, which may be an extension of the body lower wall 32-, parallel to and above the depressed lower Wall portion 36. The impact chamber 34 is open at the side toward the inlet end of body 22 so that the open end is exposed to the direct impingement of inl t air entering the body during operation of the engine. A connecting tube fitting 42 extends from the depressed lower wall 36 and communicates impact chamber 3 with the engine crankcase 12 through tubular means such as hose 44 connecting with the engine crankcase at connection 46.

At the air inlet end, diagonal slots 48 are provided in the side walls of tubular body 22 near impact chamber 34 carrying a pivot pin 50 secured therein and extending between the side walls or" the body. A butterfly valve 52 is pivotaliy mounted on pivot pin 5t} and extends in the closed position nearly across the inlet opening of body 22 including the open end of impact chamber 34 but spaced from the end of partition 40 allowing a passage for continuous communication of impact chamber 34- with the interior of body 22. A metal spring 54 engages impact lip 3a and a hole 5: in butterfly valve 52 to bias butterfly valve 52 toward the closed position.

In operation butterfly valve 52 remains closed, as shown in FIGURE 2, during engine idle and at very low throttle openings resulting in a slight pressure reduction or vacuum within body 2.2 downstream from the valve 52 and causing a flow of eflluents from crankcase 12 through hose 44, tube fitting 42 and impact chamber 34 and between the end partition 4-iland the lower end of butterfly valve 52, into the inlet air stream passing through body 2?. to the engine air inlet. Upon opening of the engine throttle, causing increased air flow through body 22, an increase in vacuum occurs therein which actuates butterfly valve 52 toward the open position, shown in FIGURE 3, the degree of opening depending upon the vacuum created in body 22 and being related to the resulting air flow.

As butterfly valve 52 opens, the lower end thereof is lifted upwardly and outwardly, opening a direct flow path between impact chamber 34 and the atmosphere thereby allowing inlet air to impinge directly upon the open end of impact chamber 34. This impingement results in a ram efifect which tends to offset the effects of the increased vacuum in body 22 by preventing an equivalent increase in the vacuum in impact chamber 34. Since tensions giving the larger depressions.

the flow of crankcase effluents is largely dependent'upon I the vacuum in impact chamber 34, the effect is to provide a fiow of crankcase effluents which is relatively constant j under all conditions of engine operation or which tends to increase less with increased throttle opening than would otherwise be the case. 7

The actual flow characteristic obtained with the crankcase ventilationcontrol device is dependent upon the relative dimensions of its various portions which may be experimentally determined to give the desired characteristic fora specific application. The protrusion of the impact lip 33 beyond the inletcend of body 22 .is a 7 It was found in a particular instance that with the impact lip formed flush with particularly important variable.

the body inlet end, a maximum crankcase depression of approximately 16 inches of water was obtained; while extending the impact lip out to .60 inch beyond the body inlet end reduced the maximum crankcase depression to approximately 3 inches of water. In addition; it was found that by varying the tension of spring 54, the crankcase depression at engine idle could be varied within a range or" from /2 to 6 inche's'of water, the greater spring Obviously, the variation of other dimensions, such as location of the'pivot pin'Sil and angular relation of the upper and'lower porfiow characteristics obtained and such changes are within the scope of this invention.

It is apparent that numerous'modification's of the in vention disclosed herein could'be made without departing from the underlying inventive concept; for example, the impact chamber 34 may be modified in size or shape tions of the butterfly valve 52 could likewise affect the or made as merely a portionof connecting tube fitting 4t). 7

Further, the open end of the impact chamber may be disposed in any suitable location within the inlet air stream and the opening need not be in the direct flow path if suitable means are provided to direct a portion of the inlet air so as to impinge uponrthe opening. Furthermore, the impact chamber opening could ,be formed on a movable member such that it could be adjusted into, or outof, the direct path of the inlet air in response to the flow characteristic desired. Additionally, such means as may be provided for controlling the flow of inlet air against the impact chamber opening or into the engine air inlet could be of substantially different configuration than that herein disclosed as long as the purpose of the means is substantially the s arne as'the butterfly arrangement herein disclosed.v a a These and other modifications which may be made within the scope of the invention shown herein may be considered as falling within this invention which is to be limited only bythe'language of the appended claims.

What is claimed is: a 1, For use in combination with aninternal combustion engine having a crankcase and an air inlet, a crankcase ventilation control device comprising tubular means ventilation control device comprising tubular means adapted to be connected to said air inlet and defining a fiow path for the inlet air, connecting means on said tubular means adapted to be connected to said crankcase and defining an opening for admitting crankcase efliuents into said flow path against the direction of flow of the inlet air stream, saidropening being subject to the impingement of a portion of said inlet air stream and adapted to utilize the ram, effect of said inlet air stream to decrease the vacuum created in said connecting meansby engine operation, and valve means in said tubular means arranged to block the flow of engine inlet air against said opening to reduce said ram effect of the inlet air stream when the inlet air flow is low and operative upon increasing air.

flow to correspondingly remove the blockage and allow said ram eiect to occur in proportion to the inlet air connected to said-crankcase to receive crankcase efliuents therefrom, said connecting means terminating in said tubular body in an opening facing opposite the direction of air flow, butterfly valve means pivotally mounted in said body and spring biased to afposition substantially blockingthe flow of inlet air directly into said opening while allowing free flow between said opening and the portion of said body communicating with said air cleaner, said valvemeans being responsive toincreasing vacuum in said body to correspondingly movetoward a position wheretsaid opening is substantially unblocked, allowing to r a correspondingdegree the full force of the inlet air to impinge on said opening to regulate the value of the vacuum in said connecting means in" a predetermined manner. I

6. For use in combination with an internal combustion engine having a crankcase and an air cleaner silencer including an inlet tube, a crankcase ventilation-control device comprising an open ended tubular, body of generally rectangular cross section having inlet and outlet ends and adapted tofbe connected at the'outlet end to said inlet tube, means defining an impact chamber formed in said body at the inlet end thereof including a partition extending from the adjacent lower wall portion of said body and separating said chamber from the balanceof the interior of said. body, and a depressed lowerwall spaced 7 below said partition and having an impact lip -extending adapted to be connected to said air inlet and defining a flow path for the inlet airi-ncluding connecting means on said tubular lmeans defining an opening for admitting crankcase eifluent into said flow pathin response, to vacmin: created in said tubular means by engine operation, 1

said opening being subject to the impingement or a portion of said inlet air stream and adapted to utilize the ram effect of said inlet air stream to partially offset the eflect of said vacuum.

therefrom for a predetermined dimension beyond the other portions'oi' said inlet end, said chamberibeing open at the end toward said'body inlet end, a tube fitting .ex-

tending from an exterior wall of said chamber and, "adaptedito communicate said chamberwith's'aid engine crankcase, a pivot pin carried by opposite walls of said body; a butterfly valve pivotally mounted onsaid pivot :pin and extending in the* closed position substantially across the entrance to saidbodylinlet end and said cham ber open end and spacedfromthe end of saidpartition 2. The device of claim 1 including means for controlling the flow of inlet air against said opening whereby to modify said ram effect in a predeterm ned manner.

3. The device'of claim 1 including valve means-responsive to the" inlet air how to control the impact'of said air on-said opening whereby'to modify said ram efifect in a predetermined manner in relation to inlet air flow. 7

4. For use in combinationiwith an internal combustionv engine having a crankcase'andzan' airinlet, a crankcase.

whereby communication between said chamber and the interior of said body is continuously maintained, spring means engaging said body and urging said butterfly valve toward the closed position, said butterfly valve being adapted to remain closed when air flow through said body is relatively: low whereby a vacuum is created in said 1 body causing ja flow of crankcase efiiuents'from said crankcasethrough said tube fitting and into, the air stream passing through said body and said butterfly valve being adaptedupon'increasing vacuumin said body to open an amount corresponding tothe resulting increase in air flow through said body whereby to admit in corresponding degree a portion of the flow of inlet air to impinge directly upon the open end of said chamber to offset the effect of increasing vacuum existing in said body and to hold the vacuum in said impact chamber relatively constant.

References Cited in the file of this patent UNITED STATES PATENTS Orem July 5, 1927 Clason June 3, 1930 Kamrath Feb. 28, 1933 McKinley May 2, 1933 

1. FOR USE IN COMBINATION WITH AN INTERNAL COMBUSTION ENGINE HAVING A CRANKCASE AND AN AIR INLET, A CRANKCASE VENTILATION CONTROL DEVICE COMPRISING TUBULAR MEANS ADAPTED TO BE CONNECTED TO SAID AIR INLET AND DEFINING A FLOW PATH FOR THE INLET AIR INCLUDING CONNECTING MEANS ON SAID TUBULAR MEANS DEFINING AN OPENING FOR ADMITTING CRANKCASE EFFUENT INTO SAID FLOW PATH IN RESPONSE TO VACUUM CREATED IN SAID TUBULAR MEANS BY ENGINE OPERATION, 